Single-Axis Linear Motion System

ABSTRACT

A linear motion system utilizing one or more printed circuit boards embedded within a stage wherein the system components, including the controller, drive, and controller, may be mounted to a printed circuit board (PCB), and the electrical communications between the system components and the power to the system components are supplied through traces or etchings on the printed circuit board, thereby omitting the need for additional power and communication cables.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 62/461,383, filed Feb. 21, 2017 and titled “Motor coil,Encoder and Drive on a Printed Circuit Board and Method of Making andUsing Same,” the disclosure of which is herein incorporated byreference.

BACKGROUND

Linear motion systems are used to produce precise linear motion along atleast one axis of direction. Applications of linear motion systemsinclude any application in which linear motion may be desired. This typeof motion is useful in robots, actuators, tables/stages,fiberoptics/photonics alignment and positioning, assembly, machinetools, semiconductor equipment, electronic manufacturing, visionsystems, and in many other industrial automation applications. Otherapplications of linear motion systems include precision medicalapplications, such as automated digital microscopy which supports a widerange of applications, including cellular imaging and diagnosticinstruments, automated inspection and metrology, and DNA sequencing. Inmicroscopy, linear motion systems may be used to control the verticalposition of an objective as well as control the position of a specimenin a horizontal plane perpendicular to the axis of an objective.

In a typical linear motion system, a moving carriage can be driven (madeto move back and forth) with a variety of motors. These can include, forexample, piezo actuators, linear motors, rotary motors and screws,rotary motors and belts, and rotary motors and rack and pinion. Linearmotors used in a linear motion system typically include an array ofmagnets and one or more coils that carry current. The array of magnetsmay produce a static magnetic field, whereas the coils produce atime-varying magnetic field that depends on the current flowing throughthe coils. The magnetic field produced by the coils interacts with thestatic magnetic field to generate a force. For example, in someconfigurations, the produced force may be linearly proportional to thecurrent and the static magnetic field. The force that is generated canbe controlled by controlling the current flowing through the coils. Inparticular, an electronic motion controller is used to determine theamount of current that should flow through the coils to produce theintended motion. An electronic drive can receive logic-level commandsfrom the electronic controller and translate those commands into thecurrents that flow through the one or more coils.

Generally, linear motion systems include a stage featuring a stationarybase and a moving carriage. In a linear motion system including a linearmotor, current flows through the one or more coils of the linear motor.The moving carriage can move relative to the stationary base along alinear axis. To guide the moving carriage along a straight line, thestage can include linear guideways. In addition, the linear motion stagemay include an encoder, which can measure the position of the movingcarriage relative to the stationary base. A position signal from theencoder may be provided to the controller to assist the controller indetermining the correct amount of current to be supplied by the drive tothe one or more coils to achieve a desired position. Such linear motors,which use position feedback to control motion and final position, arereferred to as linear servomotors.

Traditional linear motion systems suffer from a number of problems. Forexample, interface cables must be provided that connect the drive andcoils. Such interface cables increase the cost of materials of a linearmotion system as well as the cost of assembly. This setup requiresinterface cables, often containing up to fifteen conductors per cable.This arrangement also requires special routing features for the cablingto exit the system to the drive. In addition, the controller, drive, andinterface cables increase the weight and size of the linear motionsystem.

Traditional linear motion systems require multiple components (i.e.,motor, encoder, drive, etc.) to be assembled in a potentially laborintensive process. Connections are typically made using expensivecabling and connectors. This cabling carries sensitive, critical signals(i.e. encoder feedback) and high motor currents.

Two linear motion stages may be combined to form a dual-axis linearmotion system. For example, a first linear motion stage may providemotion along an x axis, whereas a second linear motion stage may providemotion along a y axis that is perpendicular to the x axis. Dual-axislinear motion stages are typically formed from at least three plates,which are usually metal. In particular, a typical dual-axis linearmotion system includes a base plate, a top plate, and a third centerplate that separates the base plate and top plate.

In addition to the above problems, two-axis linear motion systems sufferfrom additional problems. For example, the presence of the third centerplate adds bulk, weight, and cost to the system.

It is, therefore, an object of the present disclosure to overcome theabove problems and others by providing a linear motion system withintegrated components such as controller, drive, motor and encoder. Inaddition, it is an object of the present disclosure to overcome theabove problems by providing a miniaturized stage. Furthermore, it is anobject of the present disclosure to overcome the above problems byproviding a motion system that is more cost-effective to manufacture.

SUMMARY

The present disclosure is directed generally to a linear motion systemutilizing one or more printed circuit boards embedded within a stagewherein the system components are mounted to the printed circuit board(PCB), and the electrical communications between the system componentsand the power to the system components are supplied through traces oretchings on the printed circuit board, thereby omitting the need foradditional power and communication cables. The embedded PCB can includea controller and drive integral to the PCB. The controller and drive maybe separate components soldered to the PCB, or the controller and drivemay be combined into a single component. The current signal output fromthe drive may be transmitted to one or more coils via tracings in thePCB. The controller is a set of electronics that takes commands eitherstored in it or sent from a host computer, and interprets these to causethe appropriate motion to occur. It sets up a desired trajectory ofvelocity vs. time, controls the start and final positions, and allpositions in-between, by implementing a servo loop in which desired andactual position (from the encoder) are compared, and current commandsare sent to the electronic drive to cause the coil currents to beupdated at high speed (up to 20K times a second) to force the movingcarriage to the correct position, velocity, acceleration, and jerk alongits required trajectory. The electronic drive includes the powerelectronics that translates logic-level commands from the electroniccontroller into the currents needed to flow in the coil.

Preferred embodiments include a linear encoder to determine the positionof the moving carriage relative to the stationary base. The encoder maybe either optical or magnetic and includes a small read head whichdetects the position along a longer encoder scale. The encoderpreferably is located internal to the stage. For example, the encodermay also be mounted to the same PCB as the controller and drive. Inaddition, the encoder may be absolute or incremental. Absolute encoderscan determine their position at power-on, but are more complicated andexpensive. Incremental encoders are simpler, cheaper and work at fasterspeeds. In at least one embodiment, the one or more coils of the linearmotor and the encoder read head are in the stationary base of the stage,and no moving cables are required. In others, the coils and/or encoderread head move, and so a set of moving cables are required.

In some embodiments, the linear motion system includes a single stagefor travel back and forth along a single direction (e.g., x). In otherembodiments, two or more stages can be combined together for travelalong two or more directions (e.g., x-y). In these other embodiments, aPCB can serve as a center structure that separates the lower base froman upper moving carriage.

The linear motion system uses linear guideways to guide the movingcarriage relative to the stationary base. The linear guideways userolling steel bearings to guide the moving carriage in a straight line.In some embodiments, the linear guideways may be crossed rollerbearings. Crossed roller bearings may include equal length stationaryand moving rails. These can be used in pairs, with two stationary railsand two moving rails. The two stationary rails can be mounted to a base,while the two moving rails can be mounted to an equally long movingcarriage. As it moves to either side of center, the moving carriageoverhangs the base and its rails.

In some embodiments, the linear guideways may be recirculating bearings.Linear recirculating bearings can include one or more long linear rails,which are stationary and fasten to a base or surface beneath them.Smaller ball-bearing trucks can be coupled to grooves in the rails thatpermit the trucks to roll along the grooves in the linear rail. In atypical single-axis system, there may be two parallel linear rails, eachwith two trucks mounted thereon, for a total of four trucks. The movingcarriage can be attached to these four trucks. A recirculating bearingsystem typically has a long stationary base and a shorter movingcarriage that rolls along the rails. The rail length minus the carriagelength generally may determine the available travel. In someembodiments, the linear guideways could be air bearings or flexures.

In some embodiments, the one or more coils that conduct current may bemounted to a stationary surface, such as the PCB and/or base, andmagnets may be mounted to a surface that moves relative to the coils,such as a moving carriage and/or upper plate. For example, embodimentsthat use crossed roller stages may employ one or more coils that aremounted to the PCB or base. The one or more coils that conduct currentgenerate force since they are in magnetic field of magnets which mayhave steel elements to focus the magnetic field towards the one or morecoils.

In other embodiments, the magnets may be mounted to a stationarysurface, and the one or more coils that receive current may be mountedto a surface that moves relative to the magnets. For example,embodiments that use recirculating bearings may employ coils that aremounted to the moving carriage. In these embodiments, a cable maytransfer power to the moving carriage. A PCB that includes an integralcontroller and drive may be mounted internal to the moving carriage. ThePCB may receive power from the cable, and the controller and drive maysupply current to the one or more coils. The PCB with integralcontroller and drive may also be mounted anywhere else within the stage,and a cable may connect the drive to the moving carriage to supplycurrent to the one or more coils.

In at least one embodiment, the presently disclosed technology works byfastening bearings or other linear motion elements directly to eachother with the PCB as a spacer. The presently disclosed technologyrelies on bearing rails for structure as the PCB does not undergosignificant forces. The PCB can include through holes for the bolts orother fasteners to go from the rail of the upper axis, to the tappedholes in the trucks of the lower axis. The PCB can also contain one ormore fasteners such as threaded studs that can be pressed into a PCB.

In at least one embodiment, the components can include some or all ofthe following: one or more printed circuit boards, copper magnet wirecoil(s), coil potting, position sensor(s), drive stage(s), limitswitch(es), microcontroller(s), motion controller(s), dc-dcconverter(s), communication transceiver(s), passive electronics (i.e.resistors and capacitors), and connector(s). These components can bediscrete or integrated (i.e. microcontroller with integratedcommunication transceiver and motion controller).

In at least one embodiment the motor coils, controller, and/or drive aremounted on the PCB. The encoder can be optional depending on whether theapplication calls for sensored or sensorless (i.e. Back EMF measurement)control.

In at least one embodiment, the presently disclosed technology works bysoldering and potting motor coil(s) to a PCB. The PCB can provide alldrive current and communication through its traces.

In one embodiment, the presently disclosed technology is specific tolinear motors as opposed to typical systems that use rotary motors thattranslate to linear motion. This type of motion is very common inmachine tools and factory automation where the rotary to linearconversion mechanism provides a high mechanical advantage to move aheavy load. The presently disclosed technology is most suitable forprecision medical application, such as imaging, where a small load isbeing moved with high smoothness and accuracy requirements.

In at least one embodiment, the presently disclosed technology onlyneeds communication and power to be cabled. The communication canutilize error checking. The power is inherently lower current due to thenature of the design and may utilize higher gauge, low cost conductors.

In at least one embodiment, the presently disclosed technology is idealfor low cost, compact, single or multi-axis linear motion. This is alsoideal for situations where the control electronics would be far awayfrom the motor and feedback.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe presently disclosed technology, will be better understood when readin conjunction with the appended drawings. For the purpose ofillustrating the invention, there are shown in the drawings variousillustrative embodiments. It should be understood, however, that thepresently disclosed technology is not limited to the precisearrangements and instrumentalities shown. In the drawings:

FIG. 1 is a perspective view of a single axis linear motion systemaccording to an embodiment having crossed roller bearings.

FIG. 2 is an end view of the single axis linear motion system of FIG. 1.

FIG. 3 is a top perspective of the single axis linear motion system ofFIG. 1 with the moving carriage removed.

FIG. 4 is a top perspective of the single axis linear motion system ofFIG. 1 with the moving carriage, base, stationary rails, moving rails,and magnet housing removed.

FIG. 5 is a perspective view of a single axis linear motion systemaccording to another embodiment having crossed roller bearings.

FIG. 6 is an end view of the single axis linear motion system of FIG. 5with the moving carriage removed.

FIG. 7 is a top perspective of the single axis linear motion system ofFIG. 5 with the moving carriage removed.

FIG. 8 is a top perspective of the single axis linear motion system ofFIG. 1 with the moving carriage and base removed.

FIG. 9 is an end perspective view of a single axis linear motion systemaccording to another embodiment having linear recirculating bearings.

FIG. 10 is a top perspective view of the single axis linear motionsystem of FIG. 9 with the moving carriage removed.

FIG. 11 is a top perspective of the single axis linear motion system ofFIG. 9 with the moving carriage, coil housing, and base removed.

FIG. 12 is a perspective view of a dual axis linear motion systemaccording to another embodiment having linear recirculating bearings.

FIG. 13 is a top perspective view of the dual axis linear motion systemof FIG. 12 with the base and moving carriage removed.

FIG. 14 is a perspective view of a dual axis linear motion systemaccording to another embodiment having linear recirculating bearings.

FIG. 15 is a top perspective view of the dual axis linear motion systemof FIG. 14 with the moving carriage removed.

FIG. 16 is a depiction of a two-dimensional encoder scale of FIG. 15.

DETAILED DESCRIPTION

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to illustrateelements that are relevant for a clear understanding of the invention,while eliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not facilitate a better understanding of theinvention, a description of such elements is not provided herein.

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “bottom,” “top,” “left,” “right,”“lower” and “upper” designate directions in the drawings to whichreference is made. Unless specifically set forth herein, the terms “a,”“an” and “the” are not limited to one element but instead should be readas meaning “at least one.” The terminology includes the words notedabove, derivatives thereof and words of similar import.

The figures show embodiments of linear motion system 100 according tothe presently disclosed technology are shown. Referring to FIGS. 1-4, asingle axis linear motion system 100 is shown having a base 102, whichis stationary, and a moving carriage 104, which moves relative to base102. Moving carriage 104 is movable back and forth along a singledirection. For example, the single direction of movement may be avertical direction. In FIGS. 1 and 4, the direction of movement ofmoving carriage 104 is illustrated by arrow X, while in FIG. 2, thedirection of movement of the moving carriage 104 is into and out of thepage. A payload of interest may be mounted to moving carriage 104. Forexample, a microscope objective may be mounted to moving carriage 104.

The single axis linear motion system 100 of FIGS. 1-4 uses linearguideways to guide the moving carriage 104 relative to stationary base102. In this embodiment, the linear guideways are crossed rollerbearings having two stationary rails 106 which may be mounted to base102 (one on each side of base 102). Two moving rails 108 may be mountedto a side of moving carriage 104 (one on each side of moving carriage104) facing base 102. Moving rails 108 guide moving carriage 104 in astraight line relative to stationary rails 106.

Referring to FIG. 3 which shows the single axis linear motion system 100of FIG. 1 with moving carriage 104 removed, several components may bemounted to moving carriage 104. This view illustrates that the twomoving rails 108 may be mounted to moving carriage 104. For example,screws that extend along the length of the moving rails 108 may be usedto couple the moving carriage 104 to the moving rails 108. A linearencoder 110 may be included to determine the position of moving carriage104 relative to stationary base 102. The encoder preferably is locatedinternal to the stage. Encoder 110 may be electro-optical componentsmounted on a printed circuit board (PCB) 124. For example, encoder 110(shown with component removed) in FIG. 4) may be an optical componentwhich shines a light on an encoder scale provided on the underside ofthe moving carriage 104 such that the encoder may be able to track itsmotion relative to the encoder scale. In addition, this view illustratesthat a magnet housing 112 may be mounted to moving carriage 104 using,for example, threaded fasteners 114. A home switch 137 may also beprovided on PCB. Home switch 137 shines a light across its U-shape. Thelight becomes blocked or unblocked due to movement of moving carriage104.

The single axis linear motion system 100 may optionally include amagnetic counterbalance 116 that can prevent moving carriage 104 frombecoming overextended. For example, in applications in which movingcarriage 104 is mounted for vertical movement with an attachedmicroscope objective, a sudden power outage could cause the microscopeobjective to drop and become damaged. In such situations, the magneticcounterbalance 116 could provide a counterweight resistance thatprevents such a drop from occurring. For example, magneticcounterbalance 116 could be tuned to the weight of moving carriage104/objective payload. Also, another role of magnetic counterbalance 116is to allow motor power to be fully available to accelerate movingcarriage 104 and any payload rather than to create waste heat byopposing gravity. As shown in FIG. 3, magnetic counterbalance 116 caninclude a counterbalance mount 118, counterbalance tubes 120, andcounterbalance magnets 122 disposed within counterbalance tubes 120.Unlike a spring, which provides a force that is proportional tostretching distance, magnetic counterbalance 116 can provide a constantforce that is substantially constant regardless of distance of movementof moving carriage 104.

FIG. 4 illustrates the embodiment of FIG. 1 with base 102, movingcarriage 104, stationary rails 106, moving rails 108 and magnet housing112 removed. Accordingly, this view presents a clear perspective of thePCB 124, which is mounted on base 102. An integrated controller anddrive 126 is mounted on the PCB 124. Magnet housing 112 (not illustratedin this view) can house a set of upper magnets 128 and lower magnets130, with one or more stationary coils 132 sandwiched in between.Current can be supplied to the one or more coils 132 from the drive 126via PCB 124. Current flowing through the one or more stationary coils132 causes the upper magnets 126 and lower magnets 128 (and thus movingcarriage 104, on which the upper magnets 126 and lower magnets 128 aremounted by way of magnet housing) to move relative to the one or morestationary coils 132.

PCB 124 may include one or more ports 134 (FIG. 1) for providingcommunications and power. For example, a user may control single axislinear motion system 100 using an external computer. A user may use thecomputer to send motion commands to the single axis linear motion system100. No moving cables are required when the PCB is located in thenon-moving part such as base 102.

Referring to FIGS. 5-8, an alternative embodiment of a single axislinear motion system 200 is shown also using crossed roller bearings.Hereinafter, the elements of alternative embodiments having similarcharacteristics as those previously described shall be indicated withthe same reference numbers increased by 100 units. Single axis linearmotion system 200 includes an integrated PCB 224 having a controller 226mounted thereon. This embodiment features a different configuration ofmagnets, which may be housed within a moving carriage 204.

The components illustrated in FIGS. 5-8 are substantially the same as inthe embodiment of a single axis linear motion system 100 of FIGS. 1-4,except this embodiment of a single axis linear motion system 200 lacksthe optional magnetic counterbalance 116. Also, in this embodiment of asingle axis linear motion system 200, magnets 228 are mounted on movingcarriage 204. For example, a first of several magnets 228 is visible onone end of moving carriage 204 (FIG. 5). Two stationary rails 206 whichmay be mounted to base 202. Two moving rails 208 may be mounted to amoving carriage 204 with, for example, threaded fasteners 240.

FIG. 6 illustrates single axis linear motion system 200 with the movingcarriage 204 removed. Magnets 228 (which are housed within movingcarriage 204) are shown.

Base 202 includes PCB 224 (FIGS. 7 and 8) mounted thereon. A coilhousing 236, which houses the one or more coils 232, may be mounted onPCB 224 and/or base 202. An air gap 238 (FIG. 6) separates coil housing236 and magnets 228.

Referring to FIG. 7, which shows single axis linear motion system 200with moving carriage 204 removed, several magnets 228, which are mountedwithin moving carriage 204, may be arranged in a row.

Referring to FIG. 8 which shows single axis linear motion system 200with base 202 and moving carriage 204 removed, one or more coils 232mounted on PCB 224 are shown. Current is supplied to the one or morecoils 232 from the controller/drive 226 via PCB 224. At least one linearencoder 210 positioned beneath moving rails 208 may be included todetermine the position of moving carriage 204 relative to stationarybase 202.

Referring to FIGS. 9-11, an alternative embodiment of a single axislinear motion system 300 is shown which uses linear recirculatingbearings. Linear motion system 300 preferably has an integrated PCBhaving a controller mounted therein.

Referring to FIG. 9, this recirculating-bearing embodiment features abase 302 with a long row of stationary magnets 328. Each side of baseincludes a stationary rail 306A, 306B that extends along the length ofbase 302. A moving carriage 304 can be mounted on trucks 342 that movealong rails 306. For example, moving carriage 304 may be coupled to theleft rail 306A using a set of two trucks 342 (more clearly shown in FIG.10) and may also be coupled to the right rail 306B using another set oftwo trucks 342. This view also illustrates the through holes 348 presentin moving carriage 304 used to connect moving carriage 304 to each ofthe four trucks 342.

Coils 332 can be located within moving carriage 304. Communications andpower may be supplied to moving carriage 304 using cable 344.Accordingly, cable 344 can be adapted to flexibly move such that itremains coupled to the moving carriage 304 as it moves. In someembodiments, a PCB 324 with integrated controller/drive, and coils 332may be disposed within moving carriage 304. The PCB 324 with integratedcontroller/drive may receive communications and power from the cable 344such that movement commands are converted into the appropriate currentsignals that are supplied to coils 332. The coil 332/PCB 324 assemblymay be housed within a coil housing 336 (FIG. 10). In alternativeembodiments, the PCB 324 with integrated controller/drive 334 may bemounted on the base 302, and a cable may be provided to couple thecurrent output from the drive to the coils 332. An encoder as well asother components such as those discussed above may also be mounted onPCB 324.

Referring to FIG. 10, this view illustrates single axis linear motionsystem 300 with moving carriage 304 removed.

Referring to FIG. 11, this view provides a view of single axis linearmotion system 300 without the moving carriage 304, coil housing 336, andbase 302. This view illustrates a cable 350 attached to moving carriage304 may supply power that is used to provide current to the one or morecoils 332.

Alternative to PCB 324 assembly being mounted with moving carriage 304,the PCB, controller, and drive may be located elsewhere within thebase/stage and provide current to the coils in the moving carriage via acable.

Referring to FIGS. 12-13, an alternative embodiment of a dual axislinear motion system 400 is shown which uses linear recirculatingbearings. This embodiment features two linear motion stages providingtwo axes of motion and includes a third center plate which is a PCB 424,which incorporates a controller/drive 426, motor coils and encoder foreach axis of movement.

Referring to FIG. 12, dual axis linear motion system 400 is shown thatis used position, for example, a lens tube/objective payload 452relative to a base 402.

In the illustrated embodiment, two x-axis stationary rails 406 may bemounted to base 402. PCB 424 has trucks 442 mounted to its undersidethat move along x-axis rails 406 in the x-direction. Two y-axis rails408 are mounted to the topside of PCB 424.

A moving carriage 404 has trucks 454 mounted to its underside formovement along y-axis rails 408. Accordingly, by varying the x-axismovement and y-axis movement, the moving carriage 404, having lenstube/objective payload 452 attached thereto, may be controlled to movein x and y directions.

Referring to FIG. 13, a first bottom set of magnets 430 that are used toprovide movement in an x-direction may be mounted on base 402. Justabove the bottom set of magnets 430, and mounted to the underside of PCB424, are a set of lower coils 432.

As shown, a controller and drive 426 may be mounted on PCB 424. Tworails 408 for travel in a y-direction may be mounted to the top of PCB424. An upper set of coils 452 may be mounted to the upper side of PCB424. Above these coils 452, a top set of magnets 428 are mounted to theunderside of moving carriage 404.

Referring to FIGS. 14-15, an alternative embodiment of a dual axislinear motion system 500 is shown which uses linear recirculatingbearings. In previous embodiments that used recirculating bearings, tworails are used to provide motion in a particular direction. However, inother embodiments, any number of parallel rails may be used to providemotion in a certain direction. In this embodiment, three x-axis rails506 mounted to a base 502 are used to provide motion along an xdirection, and three additional y-axis rails 508 are used to providemotion along a y direction.

In particular, each x-axis rail 506 is coupled to a truck 542, each ofwhich features a small platform on which each y-axis rail 508 may bemounted. Another set of trucks 554 may be coupled to each y-axis rail508 and mount to the underside of a moving carriage 504.

A PCB 524 may be provided on base 502. PCB 524 may include acontroller/drive, motor coils and a two-dimensional encoder 510 thereonon each side of PCB 524. The motors coils interact with motor magnets526. Cables may be provided to couple the drive to each set of coils(not shown in this embodiment). Two-dimensional encoder 510 includes anencoder scale 510A (FIG. 16) having two sets of parallel lines at rightangles to each other in order to measure movement in both thex-direction and the y-direction,

An alternative embodiment (not shown) of a dual axis linear motionsystem uses crossed roller bearings. Instead of the linear recirculatingbearings of the embodiment of FIGS. 12 and 13, crossed roller bearingssuch as those shown in FIGS. 5-8 may be used instead for each stage.

A further alternative embodiment (not shown) of a dual axis linearmotion system uses a hybrid configuration of crossed roller bearings (asshown in FIGS. 5-8) in one direction and linear recirculating bearings(as shown in FIGS. 12-13) in the second direction. For example, thestage that provides motion in an x axis direction may use recirculatingbearings, as described above, and the stage that provides motion in a ydirection may use crossed roller bearings.

Changes could be made to the embodiments described above withoutdeparting from the broad inventive concept thereof. It is understood,therefore, that the presently disclosed technology is not limited to theparticular embodiments disclosed, but it is intended to covermodifications within the spirit and scope of the present invention asdefined by the appended claims. If not otherwise stated herein, it maybe assumed that all components described heretofore may, if appropriate,be considered to be interchangeable with similar components disclosedelsewhere in the specification or may be incorporated into otherdisclosed embodiments, unless an express indication is made to thecontrary. Although the invention has been described in terms ofparticular embodiments in this application, one of ordinary skill in theart, in light of the teachings herein, can generate additionalembodiments and modifications without departing from the spirit of, orexceeding the scope of, the described invention. Accordingly, it isunderstood that the drawings and the descriptions herein are profferedonly to facilitate comprehension of the invention and should not beconstrued to limit the scope thereof.

I/We claim:
 1. A linear motion system comprising: a base; a movingcarriage configured to move back and forth along a single lineardirection relative to the base; at least one motor coil; at least onemotor magnet; at least one printed circuit board mounted on one of thebase and the moving carriage; an electronic motion controller configuredto provide motion commands to the electronic drive; and an electronicdrive configured to translate commands from the electronic motioncontroller into currents supplied to the at least one motor coil;wherein the electronic motion controller and electronic drive aremounted on the at least one printed circuit board.
 2. The linear motionsystem of claim 1, wherein the at least one printed circuit board isdisposed between an upper surface of the base and a lower surface of themoving carriage.
 3. The linear motion system of claim 2, wherein the atleast one printed circuit board is mounted on the upper surface of thebase.
 4. The linear motion system of claim 3, wherein the at least onemotor magnet is mounted on the moving carriage, and wherein the at leastone motor coil is mounted on the at least one printed circuit boardmounted on the base.
 5. The linear motion system of claim 2, wherein theat least one printed circuit board is mounted on the lower surface ofmoving carriage.
 6. The linear motion system of claim 5, wherein the atleast one motor magnet is mounted on the base, and wherein the at leastone motor coil is mounted on the at least one printed circuit boardmounted on the moving carriage.
 7. The linear motion system of claim 1,wherein the at least one motor magnet is mounted on the base, andwherein the at least one motor coil is mounted on the moving carriage.8. The linear motion system of claim 1, wherein the at least one motormagnet is mounted on the moving carriage, and wherein the at least onemotor coil is mounted on the base.
 9. The linear motion system of claim1, further comprising at least two linear guideways configured to guidethe moving carriage relative to the base.
 10. The linear motion systemof claim 9, wherein the at least two linear guideways comprise at leasttwo spaced apart stationary rails; and wherein the electronic motioncontroller and electronic drive are disposed between the at least twospaced apart stationary rails.
 11. The linear motion system of claim 9,wherein the at least two linear guideways comprise crossed rollerbearings.
 12. The linear motion system of claim 11, wherein the crossedroller bearings include at least two stationary rails mounted on thebase and at least two moving rails mounted on the moving carriage. 13.The linear motion system of claim 9, wherein the at least two linearguideways comprise linear recirculating bearings.
 14. The linear motionsystem of claim 13, wherein the linear recirculating bearings include atleast two stationary rails mounted on the base and at least four trucksmounted to the moving carriage and configured to roll along grooves inthe at least two stationary rails.
 15. The linear motion system of claim14, further comprising a magnetic counterbalance configured to preventthe moving carriage from becoming overextended as moves relative to thebase.
 16. The linear motion system of claim 15, wherein the magneticcounterbalance comprises a counterbalance mount attached to at least onecounterbalance magnet, wherein each of the at least one counterbalancemagnet is disposed within a counterbalance tube.
 17. The linear motionsystem of claim 1, further comprising a linear encoder configured todetermine the position of the moving carriage relative to the base. 18.The linear motion system of claim 17, wherein the linear encodercomprises an encoder read head and an encoder scale.
 19. The linearmotion system of claim 18, wherein the encoder read head is mounted onthe at least one printed circuit board.